Gear shaving or gear finishing machines



J. A. MILLS GEAR SHAVING OR GEAR FINISHING MACHINES 0 Dec. 25, 1962 4Sheets-Sheet 1 Filed April 20. 196

Dec. 25, 1962 J. A. MILLS 3,069,977

GEAR srmvmc OR GEAR FINISHING MACHINES Filed April 20. 1960 4Sheets-Sheet 2 Dec. 25, 1962 J. A. MILLS G OR GEAR FINISHING MACHINESGEAR SHAVIN Filed April 20, 1960 4 Sheets-Sheet 3 Dec. 25, 1962 J. A.MILLS 3,069,977

GEAR SHAVING OR GEAR FINISHING MACHINES Filed April 20. 1960 4Sheets-Sheet 4 United States Patent Office 3,069,977 Patented Dec. 25,1962 3,069,977 GEAR SHAWNG 6R GEAR FINISHING MACHINES John Alfred Mills,24 Kingsley Ave., Melton Park, North Gosforth, Newcastle-upon-Tyne,England Filed Apr. 20, 1960, Ser. No. 23,507 Claims priority,application Great Britain Feb. 3, 1960 7 Elaims. (Cl. 90--1.6)

This invention has reference to gear shaving or gear finishing machines,hereafter referred to as gear finishing machines.

It is the common practice to finish gears by what is known as diagonalcross-axes finishing. In this method of gear finishing a gear-likecutter and gear having conjugate teeth are operated in mesh with theaxis of the cutter non-parallel to the axis of the gear and the gear istraversed in a path which is parallel to neither axis.

My invention relates particularly to machines for finishing gears bythis method of the kind comprising a frame having an overhanging portionfrom which depends a head, the head being rotatably adjustable about avertical axis, a knee positioned below said overhanging portion, a tablecarried by the knee and means for traversing the table in a path at anydesired angle to the axis of the gear, the head and table being adaptedto rotatably support intermeshing members one of which is a gear typecutter and the other the gear to be finished and either of which isdriven.

The invention has for its object to provide in a gear finishing machineof the kind set forth improved means for supporting and traversing thetable in a path at any desired angle relative to the axis of the gear.

The invention will now be described with reference to the accompanyingdrawings wherein FIGURE 1 is an elevation of a gear finishing machine ofthe kind set forth;

FIGURE 2 is a sectional elevation of the knee of said machine, the kneehaving a preferred embodiment of the invention and the section being onthe line 22 of FIG- URE 3;

FIGURE 3 is a plan view partly in section of FIGURE 2 the section beingon the line 3-3 of FIGURE 2;

FIGURE 4 is a section on the line 4-4 of FIGURE 2.

As shown in FIGURE 1 the gear finishing machine comprises a frame havingan overhanging portion 11 from which depends a head 12 which rotatablysupports a power driven gear type cutter 13, the head being rotatablyadjustable about a vertical axis. A knee 14 is positioned below saidoverhanging portion and carried by the knee is a gear supporting table15, the gear, which is designated 16, having teeth conjugate with thoseof the cutter 13. The gear is supported by stocks 16a.

The knee is provided with front and rear horizontally extending tracks17. Mounted to roll on the tracks are rollers 18 free on a shaft 19which extends transversely of the tracks, the two ends of the shaftextending substantially beyond the two rollers. The tracks and therollers are hardened and ground. The shaft is guided for axial movementby means of a horizontal frame 20 having front and rear limbs 21 and 22provided with aligned openings 23 in which are journalled hubs 24 whichare integral with the rollers and extend axially therefrom. The shaft 19passes through said hubs. Suitable means are provided to prevent axialmovement of the hubs, and therefore the rollers relative to the frame.Thus the inner faces of the rollers may bear against the outer faces ofthe limbs and retaining circlets 25 inserted in annular grooves in thehubs bear on the inner faces of the limbs.

The frame 20 at the two ends thereof is provided with centrallypositioned tenons 26 of inverted T formation, which tenons travel in Tshaped keyways 27 formed in the knee. It will be seen that by reason ofthe frame, its tenons and the keyways, the shaft and rollers must travelin a fixed path which cannot be varied.

The table 15, which carries the stocks or centres by which the gear tobe finished is rotatably supported, is provided with front and reardownwardly extending webs 29 having aligned openings positionedcentrally between the two ends of the table and the projecting ends ofthe shaft 19 fit snugly in the said openings. Further the under face ofthe table has a half bearing 30 which makes bearing contact with theshaft.

The shaft is provided with a centrally positioned vertical diametricalbore 31. Fitted in this bore is a spindle 32. The spindle extendsupwardly through the half bearing 30 and table 15 and its lower endcarries the inner race 32a of a spherical ball bearing. The outer race32b is fitted within a housing 33 carried by a feed slide 34. The feedslide, at one end thereof, carries the nut like member 35. Through thismember is screwed a feed screw 36 which is supported in bearings 37carried by a rotatable supporting table 38 fitted in a housing 39positioned centrally in the knee. The axis of the rotatable table isoo-incident with the vertical axis of the head 12. Secured to therotatable table is a downwardly extending barrel 40 which constitutes aworm wheel and meshing therewith is a worm 41 fast on a spindle 42. Thespindle can be rotated by a hand tool and when rotated it rotatesthrough the worm and worm wheel, the rotatable table 38 together withthe feed slide and its feed screw. Thus by means of the worm and wormwheel the rotatable table with feed slide and its screw can be adjustedso that the screw is in a vertical plane which is parallel to the pathin which it is desired to traverse the table 15.

The table 38 can be locked in its adjusted position by means of twolocking devices each consisting of a spindle 48 having right and lefthand screw threads on which are screwed clamping shoes 49 provided withconcave faces to bear on the periphery of the rotatable table. Byrotating the spindle 48 in the appropriate direction the clamping shoescan be moved towards each other to bear hard against the periphery ofthe rotatable table and thereby lock it against rotation. The said slide34 travels in guides 43 provided on the rotatable table 38.

The feed screw 36 has fast thereon a bevel wheel 44 which meshes with abevel wheel 45 fast on the upper end of a driving shaft 46 which extendscentrally through the said horizontal rotatably adjustable supportingtable 38. Driving shaft 46 is driven by a motor 47 carried by the kneethrough any suitable gearing.

Should it be desired to traverse the table in a path parallel to thetracks 17 the rotatable support 38 is adjusted by rotating the spindle42 so that the feed screw 36 is parallel to said path. The movement ofthe nutlike member 35 due to the rotation of the feed screw istransmitted through the slide 34, the spherical ball bearing and spindle32 to the shaft 19. The rollers 18 run on the tracks 17 and the table 15moves with the shaft. During such feed of the table there is no axialmovement of the shaft. The spindle 32 prevents movement of the tableaxially of the shaft.

If the rotatable support 38 is turned so that the feed screw 36 is nowat right angles to the tracks the travel of the slide 34 is such thatthe movement of the shaft is at right angles to the tracks and therollers do not roll on the tracks. The table will, of course, make alike movement. That is, the shaft moves axially relative to the rollers18 and hubs 23, the rollers 18 and hubs 23 being prevented from axialmovement by reason of the hubs being journalled in the aligned openingsin the front and rear limbs 21 of the frame 20 which latter can travelonly in a fixed path, and the hubs being retained in said openings bythe retaining circlets 25.

If now the rotatable support 38 is turned so that the feed screw is inan intermediate position the direction of feed of the table is theresultant of a component which moves the shaft so that the rollers runon the tracks and a component which moves the shaft axially, suchresultant being in a path which is parallel to the feed screw. Thus thedirection of the feed of the table relative to the axis of the cuttercan be adjusted as desired by adjusting the said supporting table 38 toa rotary position wherein the feed screw assumes the direction in whichit is desired to feed the table.

When the feed is such that the rollers travel on the tracks and theshaft is moved axially relative to the rollers it is found that therotation of the rollers substantially reduces the friction resisting theaxial movement of the shaft.

Provision is made for the lubrication of the rollers and their extendedhubs. Thus the shaft may be provided with axial oil passagescommunicating with vertical passages which terminate between the hubsand the holes in the frame in which they are fitted.

The gears are finished in known manner by bringing them into mesh withthe cutter which is driven, and traversing the table and therefore thegear carried thereby in a path which is parallel neither to the axis ofthe cutter nor to the axis of the gear.

The rollers may take the form of spur wheels which mesh with fixedracks, such racks constituting the tracks.

If desired the table may be carried by a pair of shafts each havingrollers to run on the tracks and in such case the feed is transmitteddirectly to the table 15.

In lieu of the feed screw and the nut-like member the slide may betraversed by a hydraulic or compressed air cylinder and piston assembly.

What I claim is:

1. A gear finishing machine comprising a frame having an overhangingportion from which depends a head rotatably adjustable about a verticalaxis, a knee positioned below said overhanging portion and a tablecarried by the knee, said head and table being adapted to supportintermeshing members one of which is a gear type cutter and'the otherthe gear to be finished, means for driving one of said members, frontand rear horizontally extending tracks carried by the knee, a transversemember with supporting means which travel on the tracks, the transversemember being capable of axial movement relative to the supporting meansand the table being mounted on the transverse member to traveltherewith, a feed slide by which said transverse member and table istraversed and means for traversing the slide, the feed slide and meansfor traversing the slide being adjustable about a vertical axis so thatthey can be set to correspond to the desired line of traverse of thetable.

2. A gear finishing machine comprising a frame having an overhangingportion from which depends a head rotatably adjustable about a verticalaxis, a knee positioned below said overhanging portion, an upper tablecarried by the knee, said head and table being adapted to supportintermeshing members one of which is a gear type cutter and the otherthe gear to be finished, means for driving one of said members, frontand rear horizontally extending tracks carried by the knee, a transversemember with rollers which run on the tracks, the transverse member beingcapable of axial movement relative to the rollers and the upper tablebeing mounted on the transverse member to travel therewith, a rotatablyadjustable lower table carried by the knee, its axis of rotation beingcoincident with the vertical axis of "the rotatably adjustable head, afeed slide and means for feeding the slide carried by the rotatabletable, means forming a driving connection from the feed slide to theupper table and means whereby the rotatably adjustable table can beadjusted about its axis so that the feed means and feed slide assume aposition corresponding to the desired path of traverse of the uppertable, the arrangement being such that the upper table will be traversedin the path predetermined by the setting of the feed means.

3. A machine as claimed in claim 2 wherein the transverse member isprovided with a frame which co-operates with fixed guide means by whichthe frame is constrained to travel in a fixed path to maintainparallelism of the transverse member and thereby maintain apredetermined angular relationship of the gear to the cutter during thetraverse of the upper table.

4. A machine as claimed in claim 2 wherein the transverse member isprovided with a centrally positioned diametrically extending bore inwhich is housed a spindle which forms a driving connection between thefeed slide and the transverse member and therefore the supporting tablecarried by the transverse member.

5. A machine as claimed in claim 1 wherein the feed means is in the formof a feed screw, means for rotating the screw and a nut-like membercarried by the feed slide and in engagement with the feed screw.

6. A machine as claimed in claim 1 wherein the transverse member isprovided with a frame which cooperates with fixed guide means by whichthe frame is constrained to travel in a fixed path to maintainparallelism of the. transverse member and thereby maintain apredetermined 3 angular relationship of the gear to the cutter duringthe traverse of the gear supporting table.

7. A machine as claimed in claim 1 wherein the transverse member isprovided with a centrally positioned diametrically extending bore inwhich is housed a spindle which forms a driving connection between thefeed slide and the transverse member and therefore the supporting tablecarried by the transverse member.

References Cited in the file of this patent UNITED STATES PATENTS PraegFeb. 20, 1951 Miller July 24, 1951

